1. Field of the Invention
The present invention relates to an electronic display apparatus, and especially to a display apparatus that can switch between a two-dimensional (2D) display mode and a three-dimensional (3D) display mode.
2. Description of Prior Art
Devices and means for displaying dynamic 3D images are under continuous development. These devices take advantage of the primary way that humans sense depth-binocular disparity. Because human eyes are offset from each other, humans see a slightly different image of the same object with each eye. The amount and shape of the difference between the two images is what the brain interprets as depth. 3D displays create this effect by producing two slightly different images of the same data. By directing each image into a separate eye, and finely controlling the differences between the images, the display leads the brain into interpreting the two images as the one object seen in 3 dimensions.
3D displays which require the observer to wear special glasses are quite well known. These displays present two different images in the same plane. The glasses select which of the two images is visible to each of the observer's eyes.
A 3D display apparatus in a binocular parallax mode (parallax barrier mode) is conventionally used as a 3D display apparatus which allows an observer to view a stereoscopic image without special glasses.
FIG. 4 shows a basic structure of a display section 110 of a 3D display apparatus used in the conventional parallax barrier mode. The display section 110 includes an image display panel 101, and a slit array panel 102 disposed in front of the image display panel 101. As shown in FIG. 5, the slit array panel 102 includes a plurality of strip-shaped non-transparent portions 105 and a plurality of strip-shaped transparent portions 106 arranged in parallel alternating fashion. A width of each non-transparent portion 105 is T, which also represents the distance separating adjacent transparent portions 106.
In the case where a double-window display is provided, a plurality of strip-shaped images (L) for the left eye and a plurality of strip-shaped images (R) for the right eye are alternately disposed on the image display panel 101, as shown in FIG. 6. A distance V is defined between adjacent strip-shaped images (L). The distance V is set to be slightly larger than the distance T. This configuration enables stereoscopic viewing. More specifically, as shown in FIG. 7, the strip-shaped images (L) for the left eye and the strip-shaped images (R) for the right eye displayed on the image display panel 101 are separated through the slit array panel 102 disposed in front of the image display panel 101, so as to converge to two different predetermined points. Therefore, by setting a left eye 103 and a right eye 104 of an observer at the points to which images are converged, the observer can observe a stereoscopic image.
What is lacking in the prior art is a display apparatus which can be selected to operate to provide 3D viewing.